KR930001999B1 - Varnish resin composition for electric cable - Google Patents

Abstract

The varnish resin compsn. for enamel cable comprises 0.5-5 wt.% phenol resin in polyester resin prepd. by reacting at 150-250 deg.C for 8 hrs. which comprises 15-40 wt.% of tris-2-hydroxy ethyl isocyanurate in total multivalent alcohol and comprises the ratio 1/1-1/1.6 of the multivalent acid to the multivalent alcohol. The polyester resin comprises aromatic multivalent acid e.g. terephthalic acid or isophthalic acid, and the multivalent alcohol e.g. ethylene glycol, glycerine, penta edrytol, 1,1,1triethylol ethane, 1,1,1-trimethylol propane, sorbitol, manitol, dipenta edritol, 1,4- butane diol, 1,5-pentane diol.

Description

Varnish Resin Compositions for Making Enameled Wire

TECHNICAL FIELD This invention relates to the varnish resin composition for manufacturing the coating material of an enameled electric wire. Specifically, It is related with the improvement of the heat resistance of a thermosetting polyester resin.

Generally, thermosetting polyester resins for electric wires were polycondensed polyhydric acids, such as terephthalic acid and isophthalic acid, and polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethol propane, 1.4 butanediol, and the like.

However, in the case of the enameled wire using the polyester resin thus prepared, the long-term heat resistance was about 130 ° C. Therefore, in order to improve the long-term heat resistance of the conventional polyester resin to improve this, a polyester resin in which a portion of the polyester monomer is replaced with a polyhydric alcohol containing an isocyanurate ring that contributes to heat resistance has been developed. The long-term heat resistance of the group polyester resin was improved to 155 ° C.

However, in order for the long-term heat resistance of this polyester to be 155 ° C, the resultant poly must be consumed at least 90% of the total alcohol consumption in the amount of the polyhydric alcohol including the isocyanurate ring in the synthesis. When the ester resin is made of enameled wire due to its high degree of branching, cracking of the enameled wire due to lack of flexibility of the enameled wire or cracking of the enameled wire may occur, thereby degrading the quality of the enameled wire, thereby impairing the reliability of the product. There was a problem.

Therefore, the present invention has a purpose to synthesize a polyester resin having a good flexibility in the production of enameled wires with a heat resistance of 155 ℃ to solve the above problems, having an isocyanurate ring in the synthesis of polyester Ethylene glycol glycerin, 1.4 butanediol, 1.5 pentanediol, 1.4 butene-2-diol, 2.2.4.4 to reduce polyhydric alcohol usage to less than 50% of the total alcohol and give flexibility between molecular chains. Tetramethyl, 1.3 cyclobutanediol, hydroquinone dibeta, hydroxyethyl ether and the like were reacted for 8 hours at 150 ° C-250 ° C to prepare a polyester resin, followed by addition of 0.1-5% phenolic resin. It satisfies 155 ℃ and is excellent in flexibility when manufacturing enameled wires and can be manufactured at low cost. This will be described in detail below.

In synthesizing the polyester resin of the present invention, polyacid and polyhydric alcohol are used. The polyacids which may be used here include terephthalic acid, isophthalic acid, terephthaloyl dichloride, methyl, ethyl, propyl, butyl, amyl, hexyl, octyl alcohol and terephthalic acid esterified with polyhydric alcohols, such as ethylene glycol, glycerin, Pentaerythritol, 1.1.1-trimethylol ethane, 1.1.1 triethylol propane, sorbitol, mannitol, dipentaerythritol, 1.4 butanediol 1.5 pentanediol, 1.4 butene 2 diol, tris-2-hydroxy ethyl Isocyanurate and the like.

The polyhydric acid and the polyhydric alcohol are obtained by adjusting the acid / alcohol ratio to 1 / 1-1 / 1.6 and reacting the adjusted polyhydric acid and the polyhydric alcohol at 150 ° C.-250 ° C. for 8 hours. To the polyester resin obtained by using 50% or less of tris-2-hydroxyethyl isocyanurate, preferably 15-40%, 0.5-5% of a phenol resin was added, and methacresol, xylene, a crosslinking agent, and the like were added as a solvent. The lower surface polyester varnish is manufactured. At this time, the enameled electric wire obtained using the obtained polyester varnish is 155 degreeC, and its flexibility is also abundant.

Specific aspects of the invention are illustrated in the Table 1 examples below. However, the present invention is not limited to the individual embodiments but limited to the claims.

TABLE 1

After reacting each of the materials of Examples 1-4 in Table 1 at 200 ° C. for 8 hours, a solution having a resin solid content of 33% by weight was prepared by adding a mixed solvent having a ratio of metacresol: xylene 1: 1. The phenol resin is added to 3% by weight relative to the solid content and tetraalkyl titanate is added to the solid content by adding 3% by weight to prepare an enamel varnish.

The enamel varnish obtained in the above example was applied and baked 7 times on 0.3 mm copper wire to prepare a polyester enamel wire.

Enamel wire manufacturing conditions are as follows.

Softening Furnace Temperature: 590 ℃

Soburo Inlet Temperature: 490 ℃

Soburo outlet temperature: 540 ℃

Speed: 40m / min

The characteristics of the enameled wire thus obtained are shown in Table 2 below.

TABLE 2

Claims (1)

Aromatic polyacids such as terephthalic acid and isophthalic acid, and ethylene glycol, glycerin, pentaerythritol, 1.1.1-triethylolethane, 1.1.1 trimethylol propane, sorbitol, mannitol, dipentaerythritol, 1.4 butanediol, 1.5 The ratio of polyacid and polyalcohol in the polyester resin synthesized with polyalcohols such as pentanediol and the like is adjusted to 1 / 1-1 / 1.6 so that tris-2-hydroxyethyl isocyanurate is 15-40 in the total polyalcohol. A varnish resin composition for producing an enameled electric wire, characterized in that 0.5% by weight of a phenol resin is contained in a polyester resin obtained by containing 8% by weight and reacting at 150 ° C-250 ° C for 8 hours.